Appraising Research Evidence for Practice.
Appraising Research Evidence for Practice
The purpose of this assignment is to acquire the pre-requisite skills necessary to critically appraise and review a body of research literature of my choice. I will give a rationale for my choice of topic and discuss the research strategy employed to find the evidence. While critically analysing the research, I will incorporate research theory, where appropriate, and also evaluate its potential benefit to evidence based practice.
I am currently on practice at a young persons inpatient unit that admits children aged twelve to eighteen years of age. One illness, which I have found particularly interesting, and at times challenging is anorexia nervosa, due to its apparent physical and psychological complexity. I have never met any clients with this illness during my training, but soon came to realise how common the illness is among adolescents, particularly females. The onset of this disorder is seen most frequently in females between twelve to eighteen years of age and ranks third among common chronic disorders in adolescents, surpassed only by asthma and obesity (Muscari, 1998).
Staff attitudes towards treatment of this disorder appear to differ, leading to inconsistencies. Hogarth (1991) feels this is partly due to professional's frustrations as the recovery process is slow, but she also states that there is a recognised need for development of knowledge in this area. It was with these factors in mind that I chose this area for my research subject, specifically treatment and management of anorexia nervosa.
I carried out my literature search on a computer using electronic databases. I initially carried out a search on the Ovid database and requested hits from Cinahl 1982 to March 2000, Nursing Collection 1995 to March 2000 and Medline 1993 to Present. I used the titles 'anorexia nervosa' then limited the search to 'adolescents with anorexia nervosa'. The literature available in general was voluminous, however when I limited the search to 'research' and 'adolescents with anorexia nervosa' the available literature was limited on these databases and not particularly interesting. The majority of the research tended to be based around the dietary problems or the physical aspects of anorexia.
In order to try and find more appealing research I searched the web page Netting the Evidence. This site searched a variety of published research literature, and gave users the choice of carrying out a search in Medline and PubMed. I used PubMed to search the title 'anorexia nervosa' and retrieved a plethora of research in adolescents and adults. To limit my search I used the required Boolean term and searched for 'treatment' AND 'anorexia nervosa'. This search retrieved a variety of articles looking at various aspects of treatment. A lot of papers published were reviews of current research. One review titled 'Treatment of Eating Disorders in Children and Adolescents' (Dennis, et al, 1998) outlines the effectiveness of hospitalisation, cognitive behavioural therapy (CBT), interpersonal therapy, family therapy and medication for treating anorexia and bulimia. The authors followed a stepped-care, decision tree model of intervention that takes into account the effectiveness, cost and intrusiveness of the interventions. Recommendations were made for the future practitioners, which would be informative in assisting an evaluation of management with this client group.
There were many research papers that focused on the effectiveness of one or more of the above treatments. Articles studying the impact of hospitalisation on clients and their families, focused upon the treatment received by in-patients and the medium to long term outcomes, with the literature studying the benefits of inpatient care (Kreipe, 2000, Le Grange, 1999, Yager, 1988,). However Elvins, et al, (2000), using a controlled trial, demonstrated how the 21 cases that received inpatient care had a significantly worse outcome than the 51 who had never received inpatient treatment and conclude that the negative consequences of in-patient treatment are neglected in research.
There were many research papers that focused on the use of frameworks or models to treat symptoms of anorexia nervosa, particularly with inpatients. Psychotherapy (Israel and Steiger 1999, Maynors and Wallis, 1989, Sobel, 1996), cognitive behavioural therapy (CBT) (Mitchell and Peterson, 1999, Sloan, 1999, Halmi and Sunday, 1997) and behaviour modification programmes being the most prominent. The research into the use of psychotherapy and CBT in the treatment of anorexia, demonstrated a consensus of literature which suggested that these therapy treatments are helpful in reducing symptoms of anorexia and other eating disorders, with CBT being superior to other ...
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There were many research papers that focused on the use of frameworks or models to treat symptoms of anorexia nervosa, particularly with inpatients. Psychotherapy (Israel and Steiger 1999, Maynors and Wallis, 1989, Sobel, 1996), cognitive behavioural therapy (CBT) (Mitchell and Peterson, 1999, Sloan, 1999, Halmi and Sunday, 1997) and behaviour modification programmes being the most prominent. The research into the use of psychotherapy and CBT in the treatment of anorexia, demonstrated a consensus of literature which suggested that these therapy treatments are helpful in reducing symptoms of anorexia and other eating disorders, with CBT being superior to other psychotherapies (Maynors and Wallis, 1989, Patel et al, 1998, Sloan, 1999, Israel, et al, 1999, Sunday and Halmi, 1997, Yarger, 1988). Research has also demonstrated the importance of establishing an effective and therapeutic nurse-patient relationship, before undertaking CBT with anorexic patients, as the absence of this relationship is one of the major causes of CBT failing (Patel et al, 1998, Mitchell and Peterson, 1999, Sloan, 1999).
Through my search I discovered one article titled 'To change or not to change-'how' is the question? by Treasure, et al, (1996) (appendix1) which stated that the object of its research was to apply the 'trans-theroetical' model of change to a group with eating disorders. The aim of the paper is to assess the 'stage' of change in anorexia and to measure the 'process' used to achieve change. I felt this research article was taking a different approach to other articles of the same topic and decided to find more information on the trans-theoretical model. Using the same database I searched for the title 'trans-theoretical model' AND 'anorexia', which only retrieved the one article by Treasure et al (1996). I then changed my search term to 'trans-theoretical model' and was presented with various articles, which adapted the model to assess topics such as dietary change and fat reduction (Bowen, et al, 1992, Margetts, et al, 1997), health and exercise behaviour (Marcus and Simkin, 1994, Prochaska and Velicer, 1997, Cassidy, 1997), and most prominently smoking (Carbonari et al, 1996, Fava et al, 1995, Goldberg et al, 1992). The authors of these research papers all applied the trans-theoretical model to their chosen topic in order to measure the process of change in the sample population.
Because the model had been frequently applied to other areas and appeared to be a valid and reliable measuring tool, I decided to use the research article by Treasure et al (1996), to critique, as the focus of my assignment. Also having been published in the British Journal of Medical Psychology, I felt it would be valid piece of research and useful to critique.
The title created interest for me, even though the title did not have 'anorexia' in it. I knew what topic area it would be covering therefore I read the abstract out of curiosity, however you are required to read the abstract to understand the content of the paper. Cormack (1991) suggests that cryptic titles can create certain problems and accordingly researchers may discount a valuable piece of work as being irrelevant if the only information available is contained in a vague title.
Following the title, you are presented with the author's names; unfortunately their professional or academic qualifications are not cited. The address of the eating disorders unit, where I assume the research was undertaken is given directly under the author's names, however it is not clear as to whether the author had any professional involvement with eating disorders. Cormack (1991) states that the author's professional and academic background should be explored to allow the reader to identify whether they have the appropriate experience and qualifications to undertake such a study.
The authors stated in the abstract that their objective was to apply the trans-theoretical model of change to a group of patients with eating disorders and the methodology was outlined. However even though it was stated that two questionnaires were used with one to assess 'stage' of change and the other to measure the 'process' used to achieve change, it was unclear whether the article was quantitative or qualitative in nature at this stage.
When reading the introduction I felt the authors were unclear as to the purpose of the study. The authors state that their objective was to apply the 'trans-theoretical model of change' to a group of patients with eating disorders, but they did not present a clear hypothesis for the expected outcome of applying the model. They discuss the feelings of ambivalence that clients with anorexia demonstrate towards treatment and the difficulty that carer's face working with the ambivalence and consequently having unsuccessful treatment outcomes. Therefore I am lead to assume that the purpose of the study is to gain a greater understanding of the ambivalence to enhance understanding during treatment. The design of the research so far had proved disappointing and lacking in information in areas, but despite these critical observations it still held my interest.
Through their literature review the authors discuss how the 'trans-theoretical model of change' sprang from a study of common processes among different therapeutic approaches by Prochaska (1979), and was originally developed in smokers. However the authors did not discuss which disciplinary theory the model originated from. I have attempted to search the on-line databases to find information on the original study carried out by Prochaska in 1979, but could only find his later studies, which did not offer any theory either. Interestingly none of the studies I found by Prochaska give his professional title, so I logged on AskMe.com, which allows you to ask questions through e-mail to experts in different fields. The information I received informed me that James O Prochaska is a Director of Cancer Prevention Research Consortium and Professor of Clinical and Health Psychology at the University of Rhode Island, USA. I feel this information gives credence to his studies being mostly based on cancer and the cessation of smoking and gives validation to the model. The authors regarding the validity of the model make other references, but I observed that Prochaska was included in all of these.
The authors cited no references in eating disorders and I as mentioned earlier, I also failed to find any similar research in anorexia nervosa when carrying out my own search. Thus suggesting to me that this is the first and possibly the only study of its kind addressing this particular topic. However the authors note that the trans-theoretical model has been applied in areas such as alcohol abuse and weight control, but did not elaborate further in relation to the strengths and weaknesses of these studies. The weight control they refer to I assume is in relation to studies such as 'Applying the stages of change model to dietary change' (Margetts, et al, 1992). Margetts, et al, (1992), reviewed studies which applied this model to diet. They report that the complexity of dietary change made it more difficult to apply the model in this area and studies have deferred in terms of the aspect of diet being examined, as well as algorithms and dietary assessment methodology used. This has led to difficulties interpreting results obtained. Therefore the absence of references relating to such topics may indicate that the authors were unable to conceptualise how the information could have been meaningfully integrated in to their study. A study by Stanton, et al (1986), evaluated a study of bulimic's using this model and had shown similar results to those studies undertaken in smokers. From this the authors felt the model held promise for aiding their understanding of change in bulimia.
The methodology of this research suggests that the study is quantitative. The researchers adopted a cross-sectional study, which I found appropriate because they wanted to measure the participant's responses at certain points, through the process of their illness, while being at the severe end of the spectrum of anorexia. The independent variables being studied are the 'stage' of change and the 'process' used to achieve change.
All participants were asked to complete two questionnaires, one assessing stage of change, one measuring processes of change. Surveys are often used in cross-sectional studies focusing on the make-up of the sample and are primarily designed to study the relationship and incidences of variables. Some advantages to surveys are that they provide quite simple, straightforward approach to the study of attitudes, values and beliefs and they are adaptable (Hek, et al, 1996). Disadvantages however are that data could be affected by the characteristics of the respondents possible lack of motivation, knowledge or the respondents may not answer truthfully.
The stages of change questionnaire was a brief version of the original instrument which had eight items for each of the four subscales: - precontemplation, contemplation, action and maintenance. Maintenance was omitted from this study due to participants being in-patients receiving treatment and maintenance would be more appropriate for an outpatient. A brief version of the original questionnaire was formulated leaving a six-item questionnaire. Processes of change were measured using the processes of change questionnaire for bulimia, which was modified further for use in anorexia by two of the authors.
Forty-four patients were chosen for the research and only 35 participated, the author's state the reasons for this. The participants comprised of 33 females and 2 males with the ages ranging from 15 -46 years. The only specific inclusion criteria appeared to be that all participants were inpatients and at the severe end of the spectrum of anorexia. I feel the sampling method was a convenient probability sample, considering where the research took place. There was no evidence to suggest that an ethics committee approved the research or that an explanation was given to the participants. I am also left to assume that consent was implied when the participants returned the self-completed questionnaires.
The small sample size and the modification of both sets of questionnaires for use in anorexia suggested to me that this article might be a pilot study, even though the authors do not state this. The original instrument had its reliability and validity established with other subjects in other studies. Therefore I feel the authors were testing its reliability and validity in measuring the cycle of anorexia, rather than automatically assuming it was going to be a suitable measuring tool, for this client group.
The questions were scored using a Likert scale from 1-5 indicating a range of replies from 'strongly agree' to 'strongly disagree'. Summary statistics, mean and standard error of mean were calculated for each stage and process. Probability or P values were presented in support of the analysis P< 0.05 being the least powerful result accepted as significant in research. Testing for a statistical significance appeared appropriate for the design of the study.
The authors illustrated their findings in table form and a factor analysis model and commented that there were negative correlation's between precontemplation and all the other stages and processes, but other correlation's were positive, finding an association between the two variables 'stage' and 'process'. Not surprisingly highest scores were found in the contemplation stages (considering change) and lowest in precontemplation stage (not considering any change). The data was analysed using the computer system using statistical software.
The results of the study appear to support the author's aim, which was examining the trans-theoretical model, as an association was found in the two dimensions. The discussion was objective and limitations were addressed and a balanced view on its usage in eating disorders referred to. The model has been widely used in addictive behaviours, mainly smoking, where a stage of change is relatively straight forward, as the goals appear more realistic, i.e. abstinence. The authors recognise that anorexia is more complicated, because there is a greater indication of distress.
A previous study undertaken in problem drinkers (Benefield, et al, 1993) discusses how the therapists style produced more resistance and a worse outcome than a client centred counselling approach.
Limitations for use in eating disorders were recognised and the accuracy at which a patient with complicated problems can be assigned to a single stage. However cluster analysis supports the idea that it is possible to be engaged in behaviours and attitudes described by more than one stage (Treasure, et al, 1996). The authors acknowledge that the questionnaires need to be tested on larger groups but despite limitations, compatibility with other studies was relevant. They recommend more definite studies are necessary. This model however can provide a way of thinking about helping this client group.
I felt it would have been useful if I could have read the original trans-theoretical model of change in its entirety, to gain further knowledge about its theory and it would have been interesting to find a qualitative article using this model. Giving the ambivalence and the underlying psychological factors of this client group I questioned whether a qualitative approach would have been more appropriate in attempting to understand behaviour. Avis (1994) suggests that nursing critics of quantitative approaches have pointed out the ethical and practical limitations of trying to measure such a complex phenomenon as human behaviour. They have also criticised the implicit reductionism in trying to break human action into measurable and casually linked components. However as the authors were assessing change and measuring processes and had predicted an association between two variables a quantitative method was still proved appropriate.
I feel that lack of qualitative research in this area may be because the underlying psychological factors can be quite individualised and a qualitative piece may not prove generalisability to the client group as a whole. Also the methods of data collection may prove to be too intrusive for the clients.
The interventions carried out on the unit I where I am working include individual therapy, cognitive therapy, family therapy and dairy work, which are carried out at different stages of change in the client's presentation. On comparing these interventions with the model, I felt that the model would be of little value without any psychological therapies.
Most of the research into behavioural prediction and change models suggest that both cognitive and action oriented approaches are necessary to move people from precontemplation to contemplation. The findings of the papers indicate that a combination of cognitive and action strategies may be the most effective way to target individuals who have no intention of changing their behaviour (Bowen, et al, 1992, Carbonari, et al, 1996, Fava, et al, 1995, Goldberg, et al, 1992, Marcus and Simkin, 1994, Margetts, et, al, 1997).
Swadi (2000) on discussing treatments for anorexia describes an exciting, new approach towards treatment that is based on Prochaska's theory of change and incorporates Miller and Rollnick's (1991) motivational enhancement interviewing. Swadi (2000) goes on to describe how this approach is particularly useful with resistant clients, such as adolescents, to increase their motivation to change behavioural patterns. Discovering this information allows me to conclude that that the research conducted by Treasure, et al (1996), can be used to inform nursing practice and allows areas for further development. Research is of little value unless it somehow influences the practice of nursing (Morrison, 1991).
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